With the progress of electronic information and acoustic technologies as well as the development of smart hardware products such as robots, man-machine interaction technique based on voice recognition is increasingly used in products such as mobile telephones, robots, smart sound equipments and smart television sets.
In practical applications, the first problem of the human machine interaction or human computer interaction based on voice recognition is the interference of external noise, particularly of the sound played by loudspeakers of the product itself. As both the loudspeakers and the microphone are attached to the product and very close to each other in the space, the audio played by the loudspeakers will be easily transmitted back to the system via the microphone. Therefore, the voice instruction of the user will be covered by the noise of loudspeakers and cannot be sent to the system, and the system cannot identify the voice instruction of the user. Such a phenomenon is called echo interference. Presently, echo interference has already become a problem to be solved first in the voice interaction design of smart hardware products.
The echo cancellation technology emerges accordingly. However, the current echo cancellation technology is generally for one loudspeaker only, in other words, it can cancel a single channel of noise. On the other hand, most products are designed to have two sound channels corresponding to two loudspeakers or even more sound channels. The single channel noise cancellation cannot satisfy the actual demand of products.